mineral

Milky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-waxy luster, irregular fracture, and no cleavage. It has a trigonal crystal structure, though this fragment is too rough to show crystal form; the cloudy appearance comes from microscopic fluid inclusions or fractures.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, and pegmatites, commonly in igneous and metamorphic rocks. Quartz is geologically widespread and occurs from ancient Precambrian terrains to modern hydrothermal systems.

Uses & applications

Used in glass, ceramics, electronics, abrasives, engineered stone, and aggregate; attractive pieces are collected or cut as inexpensive decorative stone. This small rough specimen has minimal commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge under pressure. Milky quartz commonly lacks the transparency required for high-value gemstones.

Field identification & locations

Identify it by its glassy/waxy appearance, white translucency, lack of cleavage, and ability to scratch ordinary glass; avoid confusing it with calcite, which is softer and cleaves readily. Common worldwide, including Brazil, the United States, Madagascar, and the Alps.